Air cleaner and muffler



Aug. 16; 1932. J. DOLZA 1,872,075

AIR CLEANER AND MUFFLER Filed Jan. 24, 1929 Patented Aug. 16, 1932 UNITED STATES PATENT OFFICE JOHN DOLZA, OF FLINT, MICHIGAN, ASSIGITOR TO GENERAL MOTORS CORPORATION, OF DETROIT, MICHIGAN, A CORPORATION OF DELAWARE AIR CLEANER AND MUFFLER Application filed January 24, 1929. Serial No. 334,765.

This invention relates to a combined air cleaner and mufiler which is particularly adapted for use on the air intake of the carburetor of an internal combustion engine. 1 5 It is an object of this invention to provide a device adapted 'to be connected to the air intake of the carburetor of .an internal combustionengine and which, when so installed, will function both to clean the air drawn into the carburetor and the cylinders by the suction of the engine and to muflle the so-called carburetor noises.

Other objects of the invention will be apparent from a perusal of the following specification and the accompanying drawing wherein there is described and shown a preferred embodiment of my invention.

In the drawing: Figure 1 is a view showing my combined 20 air cleaner and mufiler installed on the carburetor of an internal combustion engine.

Figures 2 and 3 are, respectively, a side elevation, with parts broken away and in section, and an end elevation, with parts broken away and in section, of my combined air cleaner and mufller.

In the drawing, the reference character indicates an internal combustion engine on which is installed a carburetor 11 which is provided with an air intake conduit 12 to which is connected my combined air cleaner and muffler 13.

My combined air cleaner and muifler, as shown in the drawing, includes a body portion 14: which consists of a strip of sheet metal rolled to form a spiral coil of several turns which are spaced apart, one from the other, so as to provide therebetween a spiral passageway 15. The extremity of the outer turn is preferably disposed tangentially to the main portion thereof so as to provide an enlarged opening 16 for the entrance of air into the passageway 15. In the outer wall of the body portion 14 and spaced circumferentially thereof from the entrance opening 16, there is provided a tangential dirt discharge opening 17 which is substantially coextensive in length with the body portion.

The opposite ends of the body portion are closed by heads 18 and 19, respectively, which may be secured to the body portion in any suitable manner. However, I consider it preferable, as shown in the drawing, to secure the heads to the outer turn of the body portion by soldering or welding and to secure the inner turns of the body portion to the heads by means of tongues 20 which are formed on the lateral edges of the strip of which the body portion is formed, extend through slots in the heads, and are bent over against the outer surfaces of the heads.

In the head 19, there is provided an air discharge opening 21 which is coaxial with the spiral wall of the bodyportion 14 and which;

is surrounded by an outwardly projecting air discharge conduit 22 which may be integral with the head or secured thereto in any suitable manner. Within the inner end of the conduit 22 and extending therebeyond into the interior of the body portion issecured an air-straightener element 23 which consists of a plurality of helical blades secured together to form a unit.

My combined air cleaner and mufiier is adapted, as shown in Figure 1 of the drawing, to be installed on the carburetor of an internal combustion engine with the air discharge conduit 22 in communication with the airintake conduit 12 of the carburetor, and is preferably so positioned that the air intake opening 16 of the combined air cleaner and mufiler is located adjacent the upper side thereof and opens toward the engine. When so installed and the engine is operating, the suction produced in the engine cylinders draws air through the air intake opening 16 and into the passage 15 through which it travels, due to the shape of the walls and the engine suction in a helical path. The curved path in which the air travels causes the foreign matter carried thereby to be thrown by centrifugal force to the outside of the current and against the outer wall of the body portion, and finally out of the body portion through the dirt discharge opening 17. 'After the foreign matter-has been discharged from the air, the cleaned air continues through the spiral passage 15 toward the axial portion of the combined air cleaner and mufiler. Afterentering the axial portion of the device, the

air is drawn by the suction produced in the engine cylinders into and through the air discharge conduit 22 and the carburetor l1 and into the engine cylinders.

The sound waves generated in the induction system of an internal combustion engine and which pass through the carburetor air intake into the atmosphere are the cause of the so-called carburetor noises in the engine. As they issue from the air intake of the carburetor, these sound waves are travelling in a direction parallel to the axis thereof, Since in my combined air cleaner and muf fier, the air intake opening is located in a side wall parallel to the direction of travel of the sound waves issuing from the air intake of the carburetor, there is no opening in the path of the travel of the sound waves through which they may pass into the atmosphere and consequently the carburetor noises will be muiiled. The fact that, in order to pass out of the combined air cleaner and mufier through the air inlet opening or the dirt discharge opening, the sound waves must travel in the tortuous path provided by the passage 15 and that during their travel through the passage 15 they will be reflected back and forth from the spiral walls of the body portion, losing oneach reflection a portion of their intensity, and the fact that the direction of travel of the air as it enters and passes through the device is such as to hinder the transmission of sound waves to the atmosphere through the air intake opening or the dirt discharge opening increases the efiiciency of my combined air cleaner and mufiler in mufiling the carburetor noises.

In the event that it is found that my combined air cleaner and mufller too greatly restricts the carburetor air supply, there may be provided in the head 18 an opening 2% through which air may enter and pass through the combined air cleaner and mufiier without travelling through the spiral passage 15 and which will, therefore, serve to reduce the restriction of the device.

I have found that the eliiciency of my combined air cleaner and muffier, as a muiller, may be considerably increased by providing one or more openings 25 through the spiral walls of the body portion. As shown in the drawing, the openings 25 are in the form of slots extending from a point adjacent one end of the body portion, to a point adjacent the opposite end thereof but they may be made of any other suitable shape and may be disposed otherwise than as shown in the drawing without departing from the spirit of the invention. I believe that the increase in eliiciency of the device as a muiiler which results from the provision of the opening or openings 25 may be explained on the assumption that the sound waves which pass through the opening or openings 25 interfere with the sound waves which reach the same point ne'zaore sidered as made up of two parts, a body por= tion or shell, which consists or the outer turn of the part 14:, and a bafie which consists of the inner turns of the part 14. And, as

a matter of fact, it may be desirable actually to construct the shell and the bafile as separate elements, In this event, it will be unnecessary to cut slots such as 25 in the spiral walls since when the parts of the device are assembledthe juxtaposed edges of the shell and bae may be spaced slightly from each other to provide what will be the equivalent of one or" the slots 25 in the spiral walls.

Although I have shown and described a preferred embodiment of my invention, it is to be understood that this has been done merely by way of example and that the scope of my invention is to be limited only by the appended claims. o

I claim:

1. In a device of the class described, a body which includes a continuous wall in the form of a spiral coil of several turns which are spaced apart, one from the other, to provide a spiral passageway and whose outer extremity is disposed tangentially to the main portion thereof to provide an enlarged air entrance opening, a dust discharge opening which extends through the outer turn of the Wall, heads closing the opposite ends of the spiral passageway, an air discharge opening extending through one of the heads, an air discharge conduit surrounding the opening, and a constantly open auxiliary air intake opening extending through the other head.

2. In a device of the class described, a body which includes a continuous wall in the form of a spiral coil of several turns which are spaced apart, one from the other, to provide a spiral passageway and whose outer extremity is disposed tangentially to the main portion thereof to provide an enlarged opening through which air may enter the spiral passageway, a perforation extending through the wall and communicating with two of the adjacent turns of the spiral passageway,,a dust discharge opening which extends through the outer turn of the wall, heads closing opposite ends ofthe spiral passageway, an air discharge opening extending through one of the heads, and an air discharge conduit surrounding the opening.

In testimony whereof I aifix my signature.

JQHN DOLZA. 

